Metal tube buffing and polishing apparatus

ABSTRACT

An apparatus for the buffing and polishing of metal tubing, such as steel, aluminum, brass and like metal tubing, either as the metal tubing is fed continuously from the tubing machine or tube mill or for buffing and polishing so-called off-line tubing of finite lengths. The apparatus buffs and polishes the entire outer surface of the tubing which may be cylindrical, square, or other shape, in cross sectional form. In addition, the apparatus buffs and polishes and removes the stains along the seam weld of the tubing which are formed as a result of welding the tubing along its seam line. The apparatus includes a plurality or cluster of rotary abrasive buffing and polishing wheel units each of which is operated by a first power means in the form of an hydraulic motor, and the abrasive buffing and polishing wheel units and attached hydraulic motors are movable into and out of working position by a second and pneumatic power means in the form of pneumatic piston-cylinder units. The apparatus embodies an hydraulic circuit which includes the hydraulic motors for operating the rotary abrasive buffing and polishing wheel units and an hydraulic pump which is operated by a single electric motor. The apparatus also embodies a pneumatic circuit which includes a plurality of the piston-cylinder units and associated power transmission means, for moving the abrasive buffing and polishing wheel units and attached hydraulic motors into and out of working position. The pneumatic circuit includes a master solenoid-operated directional flow control valve unit which controls the direction of flow of air through the piston-cylinder units which move the rotary abrasive buffing and polishing wheel units into and out of effective or working and retracted position. Manually operable electrical control means are provided for the hydraulic circuit and the pneumatic circuit. The invention also includes manually adjustable motion-limiting means for controlling the spacing of the upper and lower vertical buffing and polishing wheel units and the spacing of the horizontal buffing and polishing wheel units relative to each other in relation to the diameter of the metal tubing which is to be buffed and polished thereby.

United States Patent 1 Brandli et al.

[4 1 July 22,1975

1 1 METAL TUBE BUFFING AND POLISHING APPARATUS [75] Inventors: John R. Brandli, St. Charles;

Herbert Turek, Addison, both of 111.

[73] Assignee: Turek & Heller Machine, Inc., Addison, Ill.

[22] Filed: Sept. 17, 1973 [21] Appl. No.: 397,879

[52] US. Cl. 51/87 R; 15/88 [51] Int. Cl. B24B 5/38 [58] Field of Search... 51/80 A, 81 R, 87 R, DIG. 8,

5l/l34.5 F; 15/88, 97, 104.04

[56] References Cited UNITED STATES PATENTS 1,724,050 9/1929 Stratton 5l/l34.5 F 2,647,272 8/1953 Holmes 51/80 A 2,782,567 2/1957 Opalick 51/87 R 3,621,616 11/1971 Weatherell 51/87 R Primary Examiner-Al Lawrence Smith Assistant Examiner-Nicholas P. Godici Attorney, Agent, or Firm-Char1es B. Cannon apparatus buffs and polishes and removes the stains along the seam weld of the tubing which are formed as a result of welding the tubing along its seam line. The apparatus includes a plurality or cluster of rotary abrasive buffing and polishing wheel units each of which is operated by a first power means in the form of an hydraulic motor, and the abrasive buffing and polishing wheel units and attached hydraulic motors are movable into and out of working position by a second and pneumatic power means in the form of pneumatic piston-cylinder units. The apparatus embodies an hydraulic circuit which includes the hydraulic motors for operating the rotary abrasive buffing and polishing wheel units and an hydraulic pump which is operated by a single electric motor. The apparatus also embodies a pneumatic circuit which includes a plurality of the piston-cylinder units and associated power transmission means, for moving the abrasive buffing and polishing wheel units and attached hydraulic motors into and out of working position. The pneumatic circuit includes a master solenoid-operated directional flow control valve unit which controls the direction of flow of air through the piston-cylinder units which move the rotary abrasive buffing and polishing wheel units into and out of effective or working and retracted position. Manually operable electrical control means are provided for the hydraulic circuit and the pneumatic circuit.

The invention also includes manually adjustable motion-limiting means for controlling the spacing of the upper and lower vertical buffing and polishing wheel units and the spacing of the horizontal buffing and polishing wheel units relative to each other in relation to the diameter of the metal tubing which is to be buffed and polished thereby.

5 Claims, 30 Drawing Figures PATENTEDJUL22 I915 3,895463 SHEET 9 METAL TUBE BUFFING AND POLISHING APPARATUS OBJECTS An object of the present invention is to provide a new and imptoved apparatus either for the continuous buffing and polishing of metal tubing, such for example, as tubing made of steel, aluminum, brass or other metal, as the tubing is formed in an comes from the tube mill, or for buffing and polishing so-called off-line metal tub ing which has been cut into predetermined lengths.

Another object of the invention is to provide a new and improved buffing and polishing apparatus for the buffing and polishing of th entire outer surface of metal tubing.

A further object of the invention is to provide a new and improved apparatus for the buffing and polishing of metal tubing which embodies a novel construction and arrangement of abrasive buffing and polishing wheel units which are so constructed and arranged in different embodiments thereof that they may be employed to buff and polish the entire outer surface of metal tubing which is cylindrical in form, or square or generally rectangular in cross-sectional form, or embodying other shapes as seen in cross-sectional form.

An additional object of the invention is to provide a new and improved buffing and polishing apparatus for the continuous buffing and polishing of the entire surface of metal tubing, while, at the same time, buffing and polishing and eliminating the stains left on the tubing as a result of welding the tubing along the weld seam therein.

A further object of the invention is to provide in the new metal tube buffing and polishing apparatus novel pneumatically operated power means for moving the abrasive buffing and polishing wheel units into and out of effective or working position in relation to the peripheral surface and diameter of the metal tubing to be buffed and polished thereby.

Still another object of the invention is to provide in the new buffing and polishing apparatus novel control means for controlling the operation of the pneumatic power means for moving the buffing and polishing wheel units into and out of effective or working position relative to the peripheral surface and diameter of the metal tubing to be buffed and polished thereby.

An additional object of the invention is to provide novel hydraulic power means for rotating the abrasive buffing and polishing wheel units.

Still another object of the invention is to provide novel control means for controlling the operation of the hyraulic power means for rotating the buffing and polishing wheel units.

Yet another object of the invention is to provide therein novel manually adjustable motion'limiting means for limiting the movement of each pair of abrasive buffing and polishing wheel units towards each other into effective or working position and to accommodate the spacing of each pair of abrasive buffing and polishing wheel units to the diameter of the metal tubing to be buffed and polished thereby.

DESCRIPTION OF FIGURES IN THE DRAWINGS FIG. 1 is a front elevational view illustrating a typical and preferred embodiment of the invention;

FIG. 2 is an end elevational view as seen from the left-hand end in FIG. 1;

FIG. 3 is a top plan view illustrating the arrangement of the vertical and horizontal abrasive buffing and polishing wheel units embodied in the invention;

FIG. 4 is an exploded perspective view illustrating the abrasive buffing and polishing wheel units and illustrating parts of the hydraulic power means for rotating the abrasive buffing and polishing wheel units and illustrating certain parts of the pneumatic power means for moving the abrasive buffing and polishing wheel units into and out of retracted and effective or working position;

FIG. 5 is a side elevational view illustrating one of the horizontal abrasive buffing and polishing wheel units and the hydraulic operating motor therefor and illustrating parts of the pneumatic power means for moving the abrasive buffing and polishing wheel unit and its attached hydraulic operating motor into and out of retracted and effective or working position;

FIG. 6 is a top plan view on line 66 in FIG. 5;

FIG. 7 is a side elevational view of one of the counterweighted abrasive vertical buffing and polishing wheel units and illustrating part of the pneumatic power means for moving one of the vertical abrasive buffing and polishing wheel units into and out of retracted and effective or working position and illustrating parts of the manually adjustable motion-limiting means for limiting the extent to which the vertical abrasive buffing and polishing wheels may be moved toward each other into effective or working position depending upon and in accordance with the diameter of the metal tubing to be buffed and polished thereby;

FIG. 8 is a top plan view on line 8-8 in FIG. 7;

FIG. 9 is an elevational view illustrating the mounting means and the adjusting means for the vertical guiding means for guiding the metal tubing as it travels through the new buffing and polishing apparatus;

FIG. 10 is a vertical sectional view on line 10-10 in FIG. 9;

FIG. 11 is a horizontal sectional detail view on line l1ll in FIG. 9;

FIG. 12 is a schematic diagram of the hydraulic circuit and the hydraulic power means embodied in the invention for operating the hydraulic motors which operate the abrasive buffing and polishing wheel units;

FIG. 13 is a schematic diagram of the pneumatic circuit and the pneumatic power means embodied therein for moving the abrasive buffing and polishing wheels embodied in the invention into and out of retracted and effective or working position and illustrating the electrical control circuit for the first or hydraulic power means and the second or pneumatic power means embodied in the invention;

FIG. 14 is a schematic diagram illustrating the three phase electrical power circuit for the electrical operating motor for the hydraulic pump unit;

FIG. 15 is a schematic diagram of the electrical control circuit for the electrical operating motor for the hydraulic pump unit and the electrical control circuit for the solenoid-operated directional air flow control valve unit for the pneumatic system embodied in the invention;

FIG. 16 is a sectional view on line 16-16 in FIG. 1 illustrating parts of the motion-limiting means for limiting the motion of one of the vertical abrasive buffing and polishing wheel units in relation to the diameter of the metal tubing to be buffed and polishing thereby;

FIG. 17 is a sectional view on line 1717 in FIG. 1 further illustrating parts of the motion-limiting means for limiting the motion of one of the vertical abrasive buffing and polishing wheel units toward the other vertical abrasive buffing and polishing wheel unit in relation to the diameter of the metal tubing to be buffed and polished thereby;

FIG. 18 is a sectional view on line 18-18 in FIG. 6 illustrating the motion-limiting means for limiting the motion of one of the horizontal abrasive buffing and polishing wheel units toward the other horizontal abrasive buffing and polishing wheel unit in relation to the diameter of the metal tubing to be buffed and polished thereby;

FIG. 19 is a sectional detail view on line 1919 in FIG. 6 illustrating the pivotal mounting of one of the pneumatic piston-cylinder units which operates one of the horizontal abrasive buffing and polishing wheel units;

FIG. 20 is a sectional detail view on line 2020 in FIG. 1 and illustrates the pivotal mounting of the pneumatic piston-cylinder unit for one of the vertical buffing and polishing wheel units;

FIG. 21 is a sectional view on line 2121 in FIG. 1 and illustrates the pivotal mounting of the pneumatic piston-cylinder unit for the other vertical buffing and polishing wheel unit;

FIGS. 22, 23, 24 and 25 are schematic views illustrating various designs which may be embodied in the peripheral working surfaces of the abrasive buffing and polishing wheel units to enable them to be used in buffing and polishing metal tubing of various cross sectional forms;

FIG. 26 is a perspective view illustrating one of the vertical abrasive buffing and polishing wheel units and the mounting and pneumatic operating means therefor;

FIG. 27 is an enlarged sectional detail view illustrating the slidable mounting of one of the motion-limiting rod members which are embodied in the invention for limiting the movement of one of the vertical buffing and polishing wheels in relation to the diameter of the metal tubing to be buffed and polished thereby;

FIG. 28 is a detail view on line 28--28 in FIG. 7, partly in section and partly in elevation;

FIG. 29 is a sectional detail view on line 29-29 in FIG. 1;

FIG. 30 is a top plan view, partly in section, on line 3030 in FIG. 2, illustrating the motion-limiting means for the horizontal buffing and polishing wheel units and the motion-limiting means associated therewith.

GENERAL DESCRIPTION OF THE CONSTRUCTION AND OPERATION OF THE INVENTION A typical and preferred embodiment of the invention is illustrated in FIGS. 1 to 30, inclusive, of the drawings wherein it is generally indicated at 30, and comprises a main supporting frame 31 which may be in the form of an enclosed housing having a dust exhaust outlet 202, supporting framae 31 including a table top 32 and a supporting base 33. The invention includes a cluster or group or plurality of buffing and polishing wheel units, shown as four in number, and which are arranged in pairs in the form of two vertically extending buffing and polishing wheel units 34 and 35 and two horizontally extending buffing and polishing wheel units 36 and 37, all of which are rotatably mounted in a manner which will be described hereinafter.

The four brushing and polishing wheel units may be in the form of abrasive impregnated nylon, or other suitable material, to provide a peripheral abrasive surface, as will be described hereinafter, and are arranged at ninety degree intervals around a common horizontal axis or center which corresponds to the longitudinal axis of the metal tubing 38 which is fed through the new buffing and polishing apparatus to be buffed and polished, and in one form thereof each of the buffing and polishing wheel units 34, 35, 36 and 37 has a concave or inwardly extending peripheral recess or working surface 39 formed therein (FIG. 22). The peripheral or working surfaces or recesses, as 39, cooperate to form a metal tube-receiving channel 40 (FIG. 22) for the reception and passage therethrough of the metal tubing 38 which may be made of steel, brass,, aluminum, bronze or other metal, either as the metal tubing 38 is fed into the new buffing and polishing apparatus 30 directly from the tubing mill (not shown) in which the metal tubing 38 is formed, or for buffing and polishing so-called off-line tubing which has been cut into predetermined lengths and which may be fed through the new buffing and polishing apparatus in one or more passes by a drawbench type of attachment (not shown).

As shown in FIGS. 1, 3 and 4 of the drawings, the metal tubine 38 is fed from the tubing mill into the group or cluster of buffering and polishing wheel units 34-35-36-37 in the direction of the arrow 36 (FIGS. 1 and 3) and is guided by and between a pair of horizontally extending and rotatably mounted guide rollers 41-41 which are suitably rotatably mounted, as at 42, on the supporting frame 31 (FIGS. 1, 3 and 4).

As the metal tubing 38 passes between the horizontally extending guide rollers 414l, it also passes between a pair of vertically extending and vertically spaced and vertically adjustable guide rollers 4343 which are adjustably mounted on an upright supporting bracket member 44 (FIGS. 1, 2, 3 and 4), as will be described more specifically hereinafter.

After the metal tubing 38 passes between the vertically extending and vertically adjustable guide rollers 43 it passes between the horizontally extending and horizontally spaced buffing and polishing wheel units 36 and 37, which are rotated in contact with the peripheral surface of the metal tubing 38, and thence between the vertically extending and vertically spaced buffing and polishing wheel units 34 and 35, which are also rotated in contact with the peripheral surface of the metal tubing 38; thence between a pair of horizontally extending and horizontally spaced guide rollers 45 which are rotatably mounted, as at 46, on the supporting frame 31; then between a pair of vertically extending and vertically spaced and vertically adjustable guide rollers 47 which are adjustably mounted on an upright supporting bracket member 48 which is mounted on the supporting frame 31, from which the thus buffed and polished metal tubing 38 is withdrawn for use.

As the-metal tubing 38 passes between the horizontally extending buffing and polishing wheel units 36 and 37 the buffing and polishing wheel units 36 and 37 are rotated by a first power means in the form of hydraulic motors 49 and 49a (FIGS. 1, 2, 3, 4, 5, 6 and 12) with their peripheral or working surfaces, as 39 (FIG. 22), in engagement with the peripheral surface of the metal tubing 38, thereby buffing and polishing one half or 180 of the peripheral surface of the metal tubing 38. As the metal tubing 38 passes from the horizontal buff ing and polishing wheel units 36-37, it passes between and is engaged by the peripheral or working surfaces, as 39, of the vertically extending buffing and polishing wheel units 34 and 35 which are rotated by a first power means in the form of hydraulic motors 50 and 50a with the peripheral or working surfaces, as 39 (FIG. 22), of the vertical buffing and polishing wheel units 3435 engaging the peripheral surface of the metal tubing 38, thereby buffing and polishing the remaining one half or 180 of the peripheral surface of the metal tubing 38 while, at the same time, removing any weld seam stains which may be present therein from the operation of welding the seam of the metal tubing 38.

The horizontal buffing and polishing wheel units 36, and 37 are movable from retracted position into and out of working or effective position, relative to the diameter of the metal tubing 38, by a second power means in the form of pneumatic piston-cylinder units 51 and 51a, and the vertical buffing and polishing wheel units 34 and 35 are movable from retracted position into and out of working or effective position, relative to the metal tubing 38, by a similar second power means in the form of pneumatic piston-cylinder units 52 and 52a (FIGS. 4 and 7).

The first power means in the form of the hydraulic motors 49-49a-50-50a which operate the horizontal buffing and polishing wheel units 36 and 37 and the vertical buffing and polishing wheel units 34 and 35, respectively, are arranged in and form a part of an hydraulic circuit 53 which includes a pair of hydraulic pumps 54 for supplying oil or like hydraulic fluid under pressure to the hydraulic motors 49-49a-50-50a, and the hydraulic pumps 54 are driven by a single electric driving motor 55 (FIGS. 12 and 14).

The second power means in the form of the pneumatic piston-cylinder units 51-51a-52-52a, which move the horizontal buffing and polishing wheel units 36 and 37 and the vertical buffing and polishing wheel units 34 and 35, respectively, from their normal or retracted position into and out of effective or working position into and out of engagement with the metal tubing 38, are arranged in a pneumatic circuit 56 (FIG. 13), and are under the control of a master four-way solenoid-operated directional air flow control valve unit 57 (FIGS. 13 and and which will be described more fully hereinafter, and the master solenoid-operated directional air flow control valve unit 59 and the single electric operating motor 55 for the hydraulic pumps 54 are under the control of an electrical control circuit 58 (FIG. 15), which includes manually operable switch units, as will be described more fully hereinafter.

THE HORIZONTAL BUFFING AND POLISHING WHEEL UNITS 36 AND 37 AND THE SUPPORTING AND OPERATING MEANS THEREFOR As shown in FIGS. 2, 4, 5 and 6 of the drawings, the horizontally extending and horizontally spaced buffing and polishing wheel unit 36 is rotatably mounted, on the upper end portion of the driving shaft 59 of the operating motor 49 therefor and the operating motor 49 is mounted in and is suspended from a flange 117 of an L-shaped movable supporting arm 60 which is pivotally mounted, as at 61, on a generally cylindrical bearing 62, which, in turn, is mounted on a supporting block 64 which is attached to and is carried by an uproght supporting bracket 32, of the supporting frame 31 (FIGS. 5 and 29). A horizontally extending connecting link member 66 is pivotally mounted, as at 68, in a U- shaped yoke member 69 (FIGS. 5 and 6). A piston rod 70 has its outer end portion connected, as at 71, to a U-shaped yoke member 69. The piston rod 71 works in a pneumatic cylinder 72 which is pivotally mounted, as at 73, on an arm 74 of an upright supporting bracket 75, which is attached to and projects upwardly from the horizontal table 32 of the supporting frame 31 (FIGS. 5 and 19). The pneumatic piston 70 and its cylinder 72 from the power means 51 for operating the linkage 66-69-60 for pneumatically moving the horizontal buffing and polishing wheel unit 36 from a normally retracted position into and out of working or effective position relative to the other horizontal buffing and polishing wheel unit 37 and relative to the peripheral surface of the metal tubing 38.

An expansible bellows-type protective cover 76 surrounds the piston rod 70 and has its end portions attached, as at 77, to the pneumatic cylinder 72 and to the yoke 69, respectively (FIG. 5).

The pneumatic cylinder 72 has a pair of air ports 79 and 80 connected thereto for supplying air under suitable pressure to the pneumatic cylinder 72 and for discharging it therefrom, as will be described more fully hereinafter.

The supporting and operating means for the other horizontal buffing and polishing wheel unit 37 are similar to those for the horizontal buffing and polishing unit 36 previously described and hence those parts thereof which are similar and correspond to the parts of the supporting and operating means for the horizontal buffing and polishing wheel unit 36 have been given the same reference numerals followed by the additional and distinguishing reference character a (FIG. 4).

As referred to hereinbefore, the power means in the form of a hydraulic motor 49 for operating the horizontal buffing and polishing wheel unit 36 is mounted on and is suspended, as at 81, from the flange 117 of the pivotally mounted supporting arm 60 (FIGS. 1, 2 and 5) and the operating shaft 59 of the motor 49 projects above the body of the motor 49 and is suitably connected centrally to the bufiing and polishing wheel unit 36 so that the hydraulic motor 49 is horizontally movable or adjustable, as a unit, with the horizontal buffing and polishing wheel unit 36 which is operates and the power means in the form of the hydraulic motor 49a for operating the other horizontal buffing and polishing unit 37 is similarly mounted on and is suspended from the pivotally mounted supporting arm 60a (FIG. 4).

THE VERTICAL BUFFING AND POLISHING WHEEL UNITS 34 and 35 AND THE OPERATING AND SUPPORTING MEANS THEREFOR The lower and upper vertical buffing and polishing wheel units 34 and 35, respectively, are illustrated in FIGS. 1, 2, 3, 4, 7 and 8 of the drawings, and since they are both similar in construction and operation only one of them will be described in detail.

Thus the lower vertical buffing and polishing wheel unit 34, is rotatably mounted on a horizontally extending supporting arm 82 which is pivotally mounted on a horizontal shaft 83 which is mounted on an upright supporting member or bracket 84 which is supported by and projects upwardly from the horizontal table portion 32 of the supporting frame 31 (FIGS. 1, 4, 7 and 8). The power means in the form of the hydraulic motor 50 for operating the lower vertical buffing and polishing wheel unit 34 is mounted on and projects laterally from the pivotally mounted supporting arm 82 and rotates the lower vertical buffing and polishing unit 34 (FIGS. 1, 2, 7 and 8); the driving shaft 85 of the hydraulic motor 50 being suitably connected to the vertical buffing and polishing wheel unit 34 (FIGS. 4 and 8).

A counterweighted arm 86 is rockably mounted on the shaft 83 and is attached to the supporting arm 82 at one side thereof, the couterweighted arm 86 being pivotally or rockably movable with the supporting arm 82 on the shaft 83. A collar 87 is movably mounted on the shaft 83 adjacent to and is attached to the supporting arm 82, and an operating arm 88 is attached to the collar 87 at the outer side thereof (FIG. 4). A bifurcated yoke member 89 is attached to the outer end portion of the operating arm 88 and a pneumatic piston 90 has an upper end portion attached to the yoke member 89, the piston 90 working in a pneumatic cylinder 91. The lower end portion of the pneumatic cylinder 91 is pivotally mounted, as at 92, on a supporting bracket 93 which is attached to the top wall 32 of the supporting frame 31 (FIG. 2), and, as will be described hereinafter, the piston 90 and the pneumatic cylinder 91 therefor provide, in part, the power means 52 for moving the arm 88, collar 87 and the counterweighted supporting arm 86 on the shaft 83 so as to move the lower buffing and polishing wheel unit 34 and attached hydraulic motor 50 toward and away from the upper vertical buffing and polishing wheel unit 35, and from a normally retracted position into and out of effective or working position relative-to the peripheral surface of the metal tubing 38.

As shown in FIGS. 4 and 7, the lower pneumatic cylinder 91 has lower and upper air ports 99 and 100 therein, as will be described more fully hereinafter.

An expansible bellows-type protective fabric or like cover 94 surrounds the pneumatic piston 90 (FIG. 1); the upper end portion of the bellows-type cover 94 being attached, as at 95, to the pneumatic cylinder 91a and the lower end portion thereof being attached, as at 96, to the yoke 89 (FIG. 2).

It will be noted, in this connection, that the upper end portion of the pneumatic cylinder 91a for the upper vertically extending buffing and polishing wheel unit 35 is pivotally attached, as at 97, to a supporting member or bracket 98 which is attached to and is suspended from the top wall 99 of the supporting frame 31 (FIGS. 1 and 4).

The construction of the mounting means, counterweight means, and operating and power means for the upper vertically extending buffing and polishing wheel unit 35 are similar to the corresponding means hereinbefore described relative to the lower vertically extending buffing and polishing wheel unit 34 and hence those parts thereof which are similar to or correspond to parts hereinbefore described in reference to the lower buffing and polishing unit 34 have been given the same reference numerals followed by the additional and distinguishing reference character a.

THE MOTION-LIMITING MEANS FOR LIMITING THE MOVEMENT OF THE VERTICALLY SPACED AND VERTICALLY EXTENDING BUFFING AND POLISHING WHEEL UNITS 34 AND 35 TOWARD EACH OTHER The present invention includes motion-limiting means for limiting the motion of the vertically spaced and vertically extending buffing and polishing wheel units 34 and 35 toward each other under the influence of the pneumatic power means, that is, the pneumatic piston-cylinder units 52 and 52a, respectively, and related parts, as will now be described.

The manually adjustable motion-limiting means for the vertically extending and vertically spaced buffing and polishing units 34 and 35 is illustrated in FIGS. 1, 2, 7, l6, l7 and 26, wherein the manually adjustable motion-limiting means for the lower vertically extending buffing and polishing wheel 34 is generally indicated at 101, and comprises an elongated manually operated vertically extending rod member 102 which is mounted in the horizontal top wall 99 of the supporting frame 31 (FIG. 2). As shown in FIGS. 16, 17 and 26, the rod member 102 has a lower end portion 104 which is attached to a U-shaped yoke member 105 which is pivotally mounted, as at 106 on the counterweighted supporting arm 86 (FIG. 26).

As shown in FIGS. 1, 2 and 27, the rod member 102 has an externally threaded upper end portion 108 on which a motion-limiting stop member 103 is threadably and adjustably mounted, and a resilient shockabsorbing member 109 is mounted on the upper end portion 108 of the rod member 102 (FIGS. 27). The rod member 102 projects downwardly through an opening 110 in the top wall of the supporting frame or housing 31 and the resilient shock-absorbing member 109 engages a seat 111 which is formed by the upper peripheral or marginal edge portion of the top wall 99 which surround the opening 110 (FIG. 27). A second resilient rubber shock-absorbing member or washer 112 is mounted on the rod member 102 above the resilient shock-absorbing member 109 within an opening 1 13 which is formed in the top wall 114 of an auxiliary housing 115 for the resilient shock-absorbing member 109, and the housing 115 has a flange 116 at its lower end which, with the housing 114, is rigidly attached to the top wall 99 of the supporting frame 31 in any suitable manner, as by welding, (FIG. 27).

The construction and arrangement of the parts of the motion-limiting and stop means for the lower vertically extending buffing and polishing wheel unit 34 are such that when the piston 90 is moved downwardly in and relative to the pneumatic cylinder 91, this motion acts, through the yoke 89, arm 88, bearing 87 and shaft 83 to rotate the supporting member 118 and attached motion 50 and move the lower buffing and polishing wheel unit 34 upwardly toward the upper vertically extending buffing and polishing wheel unit 35. However, the extent of this movement of the lower buffing and polishing wheel unit 34 upwardly toward the upper buffing and polishing wheel unit 35 is limited by the then downward movement of the motion-limiting or stop rod member 102-104 and by the resulting engagement of the stop member 103 thereon with the resilient shockabsorbing unit 112-109 (FIG. 7).

However, the extent of the permissible movement of the lower vertically extending buffing and polishing wheel unit 34 upwardly toward the upper buffing and polishing wheel unit 35 may be varied and adjusted to accommodate the spacing of the vertical buffing and polishing wheel units 34 and 35, respectively, to metal tubing 38 of varying diameters, by adjusting the threaded stop member 103 on and relative to the motion-limiting rod member 102-104-108. This may be accomplished by manually rotating the stop member 103 on the threaded upper end portion 108 of the motion-limiting rod member 102.

The construction of the manually adjustable motionlimiting means for controlling the position and spacing of the upper vertically extending buffing and polishing wheel unit 35 are similar to the construction and operation of the manually adjustable motion-limiting means 101 for the lower vertically extending buffing and polishing wheel units 34, and hence those parts thereof which are similar to or correspond to similar parts of the manually adjustable motion-limiting means 101 for the lower vertical buffing and polishing wheel unit 34 have been given similar reference numerals followed by the additional and distinguishing reference character a. (FIGS. 1 and 16).

However, in the case of the upper buffing and polishing wheel unit 35 the downward motion thereof toward the lower buffing and polishing wheel unit 34, under the action of the pneumatic piston-cylinder units 52a (FIGS. 1, 4 and 16) causes the motion-limiting stop rod member 101a-102a-104a-108a to pivot downwardly at 106 (FIGS. 1 and 16) and permissible extent of the movement of the upper buffing and polishing wheel unit 35 is determined by the downward movement of the motion-limiting stop rod member 101a-1- a-illaa and the engagement of the adjustable stop member 103a thereon with the resilient shockabsorbing unit 109a-112a.

THE MOTION LIMITING MEANS FOR LIMITING THE MOVEMENT OF THE HORIZONTALLY SPACED AND HORIZONTALLY EXTENDING BUFFING AND POLISHING WHEEL UNITS 36 and 37 TOWARD EACH OTHER The present invention also includes manually adjustable motion-limiting means for limiting the movement of the horizontal buffing and polishing wheel units 36 and 37 toward each other and in relation to the diameter of the metal tubing 38 to be buffed and polished thereby. These manually adjustable motion-limiting means for the horizontal buffing and polishing wheel units 36 and 37 are shown in FIGS. 4, 6, 18 and 30 of the drawings and are substantially the same in construction and operation as the manually adjustable motion-limiting devices 101 and 101a for the vertical buffing and polishing wheel units 34 and 35, respectively, and which have been described hereinbefore, except as hereinafter described.

Thus, the manually adjustable motion-limiting means for the horizontal buffing and polishing wheel unit 36 is generally indicated at 119 (FIGS. 4, 6, 18 and 30) and includes a horizontally extending rod member 120 which is movably mounted in a vertical wall 121 of the supporting frame or housing 31 and includes an externally threaded outer end portion 122 on which a manually adjustable stop member 123 is threadably mounted (FIG. 2) and the rod member 120-122 projects through and works in a resilient shock-absorbing unit 124 which is mounted in a housing 125, these parts corresponding to the shock-absorbing unit 109-112 and the housing 114-114-116, therefor, as shown in FIG. 27.

The rod member 120 has an inner end portion 126 which is pivotally connected, as at 127, to a pivotal mounting member 204 on the body 128 of the supporting member 60 on which the horizontal buffing and polishing wheel unit 36 is mounted (FIGS. 18 and 30).

The construction and operation of the manually adjustable motion-limiting means for the other horizontal buffing and polishing wheel unit 37 are substantially the same as the construction and operation of the manually adjustable motion-limiting means 1 19-120 for the horizontal buffing and polishing wheel unit 36 and hence those parts thereof which are similar or correspond to parts embodied in the motion-limiting means for the vertical buffing and polishing wheel unit 34 have been given the same reference numerals followed by the additional and distinguishing reference character a (FIGS. 4 and 30). In this instance, however, the

' rod member 120a projects through a vertical wall 121a of the supporting frame or housing 31 which extends parallel to the wall 121 on the opposite side of the housing or supporting frame 31 (FIG. 3).

In the use of the present invention the extent of the movement of the horizontal buffing and polishing wheel unit 36 relative to and toward the horizontal buffing and polishing wheel unit 37, under the influence of the pneumatic piston-cylinder unit 51-70 and related parts 69-66-64-62-61-60 (FIGS. 4 and 30), may be adjusted to accommodate the spacing of the horizontal buffing and polishing wheel units 36-37 relative to the diameter of the metal tubing 38 to be buffed and polished thereby, by adjusting the threaded stop member 123 on the threaded outer end portion 122 of the rod member 120 so as to control the inward movement of the rod member 120 and the stop member 123 thereon and the engagement of the stop member 123 with the shock-absorbing unit 109-112 (FIGS. 1 and 27).

The operation of the motion-limiting means for the other horizontal buffing and polishing wheel units is substantially the same as hereinbefore described with reference to the horizontal buffing and polishing wheel unit 36 and hence need not be described in detail 5 herein.

THE ADJUSTABLE MOUNTING MEANS FOR THE VERTICALLY EXTENDING GUIDE ROLLERS 4343 AND 4747 (FIGS. 1, 3, 4, 9, and 11) As described hereinbefore, the first or front set of vertically extending guide rollers 4343 are adjustably mounted on an upright supporting member or standard 44 which, in turn, is mounted on an upright supporting bracket 131 which is mounted on and projects upwardly from the horizontal table 32 of the supporting frame 31 (FIGS. 1 and 4). The construction of the adjustable mounting for the front vertically extending and vertically spaced guide rollers 4343 is shown in detail in FIGS. 9, 10 and 11 of the drawings and will now be described, and the second or rear set of vertically extending guide rollers 47-47 are similarly adjustably mounted on an upright supporting standard 48 (FIG. 4) which is suitable mounted in the supporting frame 31.

Thus, as shown in FIGS. 1, 9, and 11 each of the front set of vertically extending guide rollers 43-43 is rotatably mounted in an anti-friction bearing sleeve member 132, which, in turn, is mounted on a headed bolt member 133. Each of the headed bolt member 133 has a reduced end portion 134 which projects through an opening 135 in a follower 136 which works in a channel-shaped groove or guideway 137 which is formed in a plate member 138 which is slidably mounted, as at 202, on the body of the upright supporting standard 44 (FIGS. 9, 10 and 11). The reduced end portion 134 of each of the headed bolt members 133 also projects through and works in a vertically extending slot 139 which is formed in the body of the upright standard 44 (FIGS. 10 and 11). The reduced end portion 134 of each of the headed bolts 133 has an externally threaded end portion 134 on which a threaded nut 140 is mounted, and each of the nuts 140 engages in a slot 141 which is formed in the body of the upright supporting standard 44 (FIGS. 10 and 11).

In the use of the front set of vertically extending guide rollers 43-43 the same may be readily adjusted and spaced vertically to accommodate them to the diameter of the metal tubing 38 which is to be buffed and polished, by loosening the nuts 140 on the headed bolt members 140 then adjusting the headed bolt members 133-134 and the follower members 136 in and relative to the body of the upright supporting standard 44, then readjusting the nuts 140 on the headed bolt members 133-133 to position the guide rollers 43-43 in the desired vertically spaced relationship relative to the diameter of the metal tubing 38 and the spacing of the vertically extending and vertically spaced buffing and polishing wheel units 34 and 35, respectively.

The construction, mounting and operation of the rear set of vertically spaced guide rollers 47-47 on the upright supporting standard 48 (FIG. 4) are similar to the construction, mounting and operation of the front set of vertically spaced guide rollers 43-43 shown in FIGS. 4, 9, 10 and 11, and as described above and hence need not be described in detail here.

THE MODIFIED FORMS OF THE BUFFING AND POLISHING WHEEL UNITS 34-35-36-37, AS SHOWN IN FIGS. 23, 24 AND The new buffing and polishing apparatus is adapted for use with metal tubing of various cross sectional forms and shapes in addition to metal tubing 38 which is generally cylindrical in cross sectional form, as shown in FIG. 22. Thus, as shown in FIGS. 23, 24, and 25, the new buffing and polishing wheel units 34-35 and 36-37 may be adapted for use with metal tubing 380 which is square or rectangular in cross sectional form (FIG. 23), and to this end the peripheral abrasive surfaces of the buffing and polishing wheel units 34a-35a and 36a-37a are shown as being straight or flat, as at 39a, rather than concave, as in the form of the invention illustrated in FIG. 22, so that the cluster of the peripheral abrasive surfaces 39a of the buffing and polishing wheel units 34a-35a-36a-37a will provide a working or polishing channel which is substantially square or rectangular in cross sectional form so that it will receive and engage all four sides of the square or rectangular shaped metal tubing 38a (FIG. 23).

Similarly, the peripheral abrasive surfaces of the buffing and polishing wheel units 34b-35b-36b-37b may be generally V-shaped in form so that when disposed in working relationship they will engage the entire external or peripheral surface of a square or rectangular shaped metal tubing 38b with the corner portions 142 of the metal tubing 38!; engaging the apices or troughs of the indented peripheral abrasive surfaces 39b of the buffing and polishing wheel units 34b-35- b-36b-37b (FIG. 24).

Likewise, the new buffing anf polishing wheel units may be adapted for use in buffing anf polishing metal tubing which is hexagonal, or the like, in cross sectional form, and such an arrangement is shown in FIG. 25 of the drawings wherein it will be seen that the indented peripheral abrasive surfaces 39c39c of the horizontal buffing and polishing wheel units 360-370 will engage the intersecting corner portions 143 of the hexagonal shaped metal tubing 38c whereas the somewhat differentially shaped indented peripheral abrasive surfaces 144 of the vertical buffing and polishing wheel units 340 and 35c will engage the parallel flat sides 145 of the hexagonal metal tubing 38a (FIG. 25).

THE POWER MEANS IN THE FORM OF THE HYDRAULIC OPERATING MOTORS 49-49a-50-50a FOR THE BUFFING AND POLISHING WHEEL UNITS 36-37-34-35 AND THE POWER TRANSMISSION MEANS THEREFOR (FIG. 12)

The power means in the form of the hydraulic motors 49-49a 5050a and the power transmission means therefor, for operating the buffing and polishing wheel units 36-37 and 34-35, respectively, are illustrated in FIG. 12, and comprise the hydraulic circuit 53 and which includes a single electric operating or driving motor 55 which is operatively connected, by suitable power transmission means 146, to pump means in the form of one or a pair of hydraulic pumps 54. The hydraulic operating circuit 53 includes a suitable oil storage reservoir 147 from which oil or other suitable hydraulic fluid is supplied to the inlet sides of the hydraulic pumps 54 from which oil or like hydraulic fluid is supplied, by way of an outlet line 148-149, and flow control or flow speed control devices 150-151-152 and 153, to the hydraulic operating motors 49-49a-5- O-50a, respectively, from which the oil or like hydraulic fluid is returned by way of outlet or return lines 154-155-156-157, respectively, and a main return line 158, to a return line filter unit 159, and thence by way of a return line 161) to the oil storage reservoir 147 (FIG. 12).

THE POWER MEANS AND POWER TRANSMISSION MEANS FOR MOVING THE BUFFING AND POLISHING WHEEL UNITS INTO AND OUT OF WORKING OR EFFECTIVE POSITION (FIG. 13)

The present invention includes a power means and power transmission means for moving each of the pair of buffing and polishing wheel units 34-35 and 36-37 in relation to the other and in relation to the peripheral surface and diameter of the metal tubing 38, and for moving the buffing and polishing wheel units 34-35 and 36-37 out of retracted position and into and out of working or effective position. Such power means and power transmission means are embodied in the pneumatic circuit 56 which is illustrated in FIG. 13 of the drawings, and which includes the four pneumatic piston cylinder units 51-5111 and 52-52a and which have heretofore been described.

The pneumatic circuit 56 includes an air reservoir 161 for supplying air under pressure from any suitable source thereof, by way of an air supply line 162 and branch lines 163 and 164, to the inlet ports 80 and 80aof the piston-cylinder units 51 and 51a, respectively. Suitable air flow control valves 165 and 166 are arranged in the air lines 163 and 164 to the piston cylinder units 51-5la, respectively, to control the flow of air under pressure therethrough and the resulting speed of movement of the horizontal buffing and polishing wheel units 36 and 37, respectively, out of retracted position and into working or effective position. Similarly, a suitable air flow control valve 167 is interposed between the outlet port 79 of the pneumatic piston cylinder unit 51 and a branch air line 168 of the pneumatic circuit 56, and a similar air flow control valve 168 is interposed between the outlet port 79a of the piston cylinder unit 51a and a branch air return line 169 of the pneumatic circuit 56 to control the speed of flow or air therethrough and the speed of movement of the horizontal buffing and polishing units 36 and 47, respectively, from operaetive or working position back into retracted position.

A branch air supply line 170 leads from the main line supply line 171 of the pneumatic system 56 to the inlet port 99 of the piston cylinder unit 52 and a branch air supply line 172 leads from the air supply line 171 to the inlet port 99a of the piston cylinder unit 52a, and suitable speed or air flow control valves 173 and 174, respectively, are interposed in the branch air supply lines 170 and 172 to control the flow or speed of movement of air therethrough and the resulting movement of the vertically extending buffing and polishing wheel units 34 and 35, respectively, from a normally retracted position into effective or working position. A branch air return line 175 leads from the air line 163 to the outlet port 100 of the piston cylinder unit 52 and a branch air line 176 leads from the air line 163 to the outlet port 100a of the piston cylinder unit 52a; suitable speed or air flow control valves 177 and 178 being interposed in the branch air lines 128 and 129, respectively, to control the speed of flow of air therethrough and the speed of movement of the upper and lower vertical buffing and polishing wheel units 34 and 35, respectively, from working or effective position back into the normal of retracted position.

The pneumatic system 56 (FIG. 13) also includes and is controlled by a master solenoid-operated four-way directional air flow control valve unit 57 (FIG. 13), and which will be described in further detail hereinafter.

The master solenoid-operated four-way directional air flow control valve unit 57 is connected by the air lines 162 air line 179 into the pneumatic system 56 and is shown in retracted position in FIG. 13, in which all of the buffing and polishing wheel units 34-35 and 36-37 are disposed in idle or retracted position.

A suitable lubricator unit 180 is provided in the air supply line 162 at one side of the master solenoidoperated four-way directional air flow control valve unit 57, to lubricate the air employed in the pneumatic system 56 and the piston cylinder units 51 and 51a and 52 and 52a embodied therein, and a suitable air pressure regulator valve 181 is also arranged in the air supply line 162 at one side of the master solenoid-operated four-way directional air flow control valve 57 (FIG. 13).

THE ELECTRICAL POWER SYSTEM FOR THE ELECTRICAL OPERATING MOTOR 54 FOR THE HYDRAULIC PUMPS (FIGS. 12 and 14) The electrical circuit for the electrical operating motor 55 for the hydraulic pumps 54 is illustrated in FIG. 14 of the drawings, wherein it is generally indi cated at 137, and includes the electric operating motor 55 for the hydraulic pumps 54.

A three phase power inlet is indicated at 183 (FIG. 14) with stationary switch contact members indicated at 184, and a movable three-contact switch member is generally indicated at 185. A three phase conductor system 185 to the three phase electrical operating motor 55 for the hydraulic pumps 54, and suitable fuses, as 187, and overload devices 188, are incorporated in the three phase electrical conductor system 186 (FIG. 14).

THE ELECTRICAL CONTROL SYSTEM FOR THE HYDRAULIC PUMP OPERATING MOTOR 55 AND FOR THE MASTER SOLENOID OPERATION DIRECTION AIR FLOW CONTROL VALVE UNIT 57 (FIGS. 13 and 15) The electrical control circuit for the three phase hydraulic pump operating motor 55 (FIGS. 1, 2 and 4) and for the master solenoid-operated four-way directional air flow control valve unit 57 (FIG. 13), is shown in FIG. 15, and is powered by a source of 115 volt single phase power connected at 190 and 58.

The electrical control circuit (FIG. 15) includes a movable manually operable motor starting switch unit 192, a movable manually operable motor stopping switch unit 203, and a holding contact unit 193 which is operated by the armature of starter 194 for the motor starter switch unit 192. The electrical control circuit (FIG. 15) also includes a motor starting coil 194 (MS), an overload contact 195, and a pilot light 196 which, when illuminated, indicates that the opening motor 55 for the hydraulic pumps 54 is in operation.

The master solenoid-operated four-way directional air flow control valve unit 57 includes a solenoid operator device 197 (FIGS. 13 and 15). This solenoid operator device 197 is arranged in the electrical control circuit (FIG. 15) which also includes a normally open manually operable switch unit 198 for controlling the energization and operation of the solenoid operator device 197,and a normally closed manually operable switch unit 199 for controlling the operation of the solenoid operator device 197 for the master solenoidoperated four-way directional air flow control valve unit 57.

The electrical control circuit (FIG. 15) also includes a control relay 200 (CR) which provides a holding action by means of closure of contact 203, to maintain the solenoid operator device 197 for the master solenoid-operated directional air flow control valve unit 57 in energized condition once it has been energized by the operation of the normally open mutually operable starter switch unit 198 and until such time as the master solenoid-operated four-way directional air flow control valve unit 57 is deenergized by operation of the normally closed manually operable switch unit 199 or until the entire circuit is deenergized of the N.C. switch unit 203. 

1. Apparatus for buffing and polishing metal tubing comprising a. a supporting frame; b. tube-guiding means carried by the said supporting frame for guiding metal tubing through the said apparatus in a direction generally parallel to the longitudinal axis of the said mEtal tubing to enable buffing and polishing operations to be performed on the peripheral surface of the said metal tubing as it is guided through the said apparatus by the said tubeguiding means; c. two pairs of buffing and polishing wheel units each having a peripheral abrasive surface and arranged in a cluster of the same at radially spaced intervals around and relative to the longitudinal axis and the path of travel of the said metal tubing as it is guided through the said apparatus by the said tube-guiding means; d. a first pair of said buffing and polishing wheel units being arranged in a horizontal plane and in coplanar horizontally spaced relationship relative to each other; e. the second pair of said buffing and polishing wheel units being arranged in a vertical plane and in coplanar vertically spaced relationship relative to each other; f. first supporting means for rotatably supporting each of the said buffing and polishing wheel units in the said first pair thereof for rotatable movement in a horizontal plane and in coplanar relationship relative to the said supporting frame and in engagement with the peripheral surface of the said metal tubing; g. second supporting means for rotatably supporting each of the said buffing and polishing wheel units in the said second pair thereof for rotation in a vertical plane and in coplanar relationship relative to the said supporting frame and in engagement with the peripheral surface of the said metal tubing; h. first pivotal mounting means for pivotally mounting each of said first supporting means and the said buffing and polishing wheel units carried thereby for pivotal movement in a horizontal plane toward and away from the peripheral surface of the metal tubing; i. second pivotal mounting means for pivotally mounting each of the said second supporting means and the said buffing and polishing wheel units carried thereby for pivotal movement in a vertical plane toward and away from the peripheral surface of the metal tubing, said second pivotal mounting means including an upper pivoted assembly and a lower pivoted assembly, said upper pivoted assembly being movable about an upper pivot axis, an upper said buffing and polishing wheel unit supported on said upper pivoted assembly and being movable therewith downwardly from a retracted position to a work-engaging position, said lower pivoted assembly being movable about a lower pivot axis, a lower said buffing and polishing wheel unit supported on said lower pivoted assembly and being movable therewith upwardly from a retracted position to a work-engaging position; j. first motion-limiting means including an upwardly-extending first rod member, first stop means manually adjustable on the first rod member to limit the extent of movement of the first rod member into the supporting frame, first connecting means attaching said first rod member to the upper pivoted assembly at a point between the upper pivot axis and the upper said buffing and polishing wheel unit whereby the first stop means limits the downward movement of the upper said buffing and polishing wheel unit; k. second motion-limiting means including an upwardly-extending second rod member adjacent to the first rod member, second stop means manually adjustable on the second rod member to limit the extent of movement of the second rod member into the supporting frame, and second connecting means attaching said second rod member to the lower pivoted assembly at a point located on the opposite side of the lower pivot axis from the lower buffing and polishing wheel unit, whereby said second stop means limits the upward movement of the lower said buffing and polishing wheel unit; l. first power means carried by each of the said first supporting means and extending vertically therefrom at one side of the said buffing and polishing wheels in the said first pair thereof for rotating each of the said buffing and polishing wheel units in the said first pair thereof in a horizontaL plane; m. second power means carried by each of the said second supporting means and extending horizontally therefrom at one side of the said buffing and polishing wheel units in the said second pair thereof for rotating each of the said buffing and polishing wheel units in the said second pair thereof in a vertical plane; n. first power transmission means for supplying power to the said first power means and to the said second power means for rotating each of the said buffing and polishing wheel units; o. third power means for moving the said buffing and polishing wheel units in the said first pair thereof and the said supporting means and the said first power means therefor in a horizontal plane on said first pivotal mounting means into and out of a normally retracted position in which the said peripheral working surfaces of the said buffing and polishing wheel units in the said first pair thereof are disposed out of position to engage the said peripheral surface of the said metal tubing and into effective or working position in which the said peripheral abrasive surfaces of the said first pair of said buffing and polishing wheel units are positioned to engage the peripheral surface of the said metal tubing as it is guided through the said apparatus by the said tube-guiding means; p. fourth power means for moving the said buffing and polishing wheel units in the said second pair thereof and the said second supporting means and the said second power means therefor in a vertical plane on the said second pivotal mounting means and out of a normally retracted position in which the said peripheral working surfaces of the said second pair of buffing and polishing wheel units are disposed out of position to engage the said peripheral surface of the said metal tubing and into effective or working position in which the said peripheral abrasive surface of the said buffing and polishing wheel units are positioned to engage the peripheral surface of the said metal tubing as it is guided through the said apparatus by the said tube-guiding means; q. second power transmission means for supplying power to the said third power means and to the said fourth power means; r. first control means for controlling the operation of the said first power transmission means; and s. second control means for controlling the operation of the said second power transmission means.
 2. Apparatus for buffing and polishing metal tubing as defined in claim 1 in which a. the said first power means and the said second power means are hydraulic motors; and in which b. the said first power transmission means is in the form of an hydraulic circuit for supplying hydraulic fluid under pressure to each of the said hydraulic motors.
 3. Apparatus for buffing and polishing metal tubing as defined in claim 1 in which a. the third power means and the said fourth power means include pneumatic piston-cylinder means operatively connected to the said first pivotal mounting means and to the said second pivotal mounting means; and in which b. the said second power transmission means is in the form of a pneumatic circuit for supplying aid under pressure to each of the said pneumatic piston-cylinder means.
 4. Apparatus for buffing and polishing metal tubing as defined in claim 2 in which the said first power transmission means includes a. hydraulic pump means for supplying hydraulic fluid under pressure to the said hydraulic circuit; and b. an electric operating motor for operating the said hydraulic pump means.
 5. Apparatus for buffing and polishing metal tubing comprising a. a supporting frame; b. tube-guiding means carried by the said supporting frame for guiding metal tubing through the said apparatus in a direction generally parallel to the longitudinal axis of the said metal tubing to enable buffing and polishing operations to be performed on the peripheral surface of the said metal tubing as it is guided through the said apparatus by the said tube-guiding means; c. two pairs of buffing and polishing wheel units each including spaced lateral surfaces and a peripheral abrasive surface and arranged in a cluster of the same at radially spaced intervals around and relative to the longitudinal axis and the path of travel of the said metal tubing as it is guided through the said apparatus by the said tube-guiding means; d. a first pair of said buffing and polishing wheels being arranged in a first plane and in coplanar spaced relationship relative to each other and at a preselected angle radially relative to the longitudinal axis of the said metal tubing; e. the second pair of said buffing and polishing wheel units being arranged in a second plane and in coplanar spaced relationship and at a preselected angle radially relative to the longitudinal axis of the said metal tubing and radially spaced relative to the side first pair of buffing and polishing wheel units; f. first supporting means for rotatably supporting each of the said buffing and polishing wheel units in said first pair thereof for rotatable movement in said first plane and in coplanar relationship relative to the said supporting frame and in engagement with the peripheral surface of the said metal tubing; g. second supporting means for rotatably supporting each of the said buffing and polishing wheel units in the said second pair thereof for rotation in the said second plane and in coplanar relationship relative to the said supporting frame and in engagement with the peripheral surface of the said metal tubing; h. first pivotal mounting means for pivotally mounting each of said first supporting means and the said buffing and polishing wheel units carried thereby for pivotal movement in the said first plane toward and away from the peripheral surface of the metal tubing; i. second pivotal mounting means for pivotally mounting each of the said second supporting means and the said buffing and polishing wheel units carried thereby for pivotal movement in the second plane toward and away from the peripheral surface of the metal tubing, said second pivotal mounting means including an upper pivoted assembly and a lower pivoted assembly, said upper pivoted assembly being movable about an upper pivot axis, an upper said buffing and polishing wheel unit supported on said upper pivoted assembly and being movable therewith downwardly from a retracted position to a work-engaging position, said lower pivoted assembly being movable about a lower pivot axis, a lower said buffing and polishing wheel unit supported on said lower pivoted assembly and being movable therewith upwardly from a retracted position to a work-engaging position; j. first motion-limiting means including an upwardly-extending first rod member, first stop means manually adjustable on the first rod member to limit the extent of movement of the first rod member into the supporting frame, first connecting means attaching said first rod member to the upper pivoted assembly at a point between the upper pivot axis and the upper said buffing and polishing wheel unit whereby the first stop means limits the downward movement of the upper said buffing and polishing wheel unit; k. second motion-limiting means including an upwardly-extending second rod member adjacent to the first rod member, second stop means manually adjustable on the second rod member to limit the extent of movement of the second rod member into the supporting frame, and second connecting means attaching said second rod member to the lower pivoted assembly at a point located on the opposite side of the lower pivot axis from the lower buffing and polishing wheel unit, whereby said second stop means limits the upward movement of the lower said buffing and polishing wheel unit; l. first power means carried by each of the said first supporting means and extending laterally therefrom at one lateral surface of the said buffing and polishing wheels in the said first pair thereof for rotatIng each of the said buffing and polishing wheel units in the said first pair thereof in the said first plane; m. second power means carried by each of the said second supporting means and extending laterally therefrom at one lateral surface of the said buffing and polishing wheel units in the said second pair thereof for rotating each of the said buffing and polishing wheel units in the said second pair thereof in the said second plane; n. power transmission means for supplying power to the said first power means and to the said second power means for rotating each of the said buffing and polishing wheel units; o. third power means for moving the said buffing and polishing wheel units in the said first pair thereof and the said supporting means and the said first power means therefor in the said first plane and on the said first pivotal mounting means into and out of a normally retracted position in which the said peripheral working surfaces of the said buffing and polishing wheel units in the said first pair thereof are disposed out of position to engage the said peripheral surface of the said metal tubing and into effective or working position in which the said peripheral abrasive surfaces of the said first pair of said buffing and polishing wheel units are positioned to engage the peripheral surface of the said metal tubing as it is guided through the apparatus by the said tube-guiding means; p. fourth power means for moving the said buffing and polishing wheel units in the said second pair thereof and the said second supporting means and the said first power means therefor in the said second plane on the said second pivotal mounting means and out of a normally retracted position in which the said peripheral working surfaces of the said second pair of buffing and polishing wheel units are disposed out of position to engage the said peripheral surface of the said metal tubing and into effective or working position in which the said peripheral abrasive surfaces of the said buffing and polishing wheel units are positioned to engage the peripheral surface of the said metal tubing as it is guided through the said apparatus by the said tube-guiding means; q. second power transmission means for supplying power to the said third power means and to the said fourth power means; r. first control means for controlling the operation of the said power transmission means; and s. second control means for controlling the operation of the said second power transmission means. 